STM32采集无人机遥控器PPM信号

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我是靠谱客的博主和谐龙猫，最近开发中收集的这篇文章主要介绍STM32采集无人机遥控器PPM信号，觉得挺不错的，现在分享给大家，希望可以做个参考。

概述

//PPM捕获初始化

void PPM_Init(void)//使用PA1做为输入中断源
{
       GPIO_InitTypeDef GPIO_InitStructure;
   TIM_ICInitTypeDef TIM_ICInitType;
       TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
   NVIC_InitTypeDef NVIC_InitStructure;
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPD; //下拉输入
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);

       /* 设置TIM2CLK 为 72MHZ */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2 , ENABLE);
   /* 自动重装载寄存器周期的值(计数值) */
TIM_TimeBaseStructure.TIM_Period=20000;//20ms中断一次
/* 累计 TIM_Period个频率后产生一个更新或者中断 */
   /* 时钟预分频数为72 */
TIM_TimeBaseStructure.TIM_Prescaler=(72-1);//1us
       /* 对外部时钟进行采样的时钟分频,这里没有用到 */
TIM_TimeBaseStructure.TIM_ClockDivision=TIM_CKD_DIV1;
TIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);

       TIM_ICInitType.TIM_Channel=TIM_Channel_2;//PA1 通道2
   TIM_ICInitType.TIM_ICFilter=0x0;
   TIM_ICInitType.TIM_ICPolarity=TIM_ICPolarity_Rising;//上升沿
   TIM_ICInitType.TIM_ICPrescaler=TIM_ICPSC_DIV1;
   TIM_ICInitType.TIM_ICSelection=TIM_ICSelection_DirectTI;//捕获源选择
   TIM_ICInit(TIM2,&TIM_ICInitType);
       NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);
NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);

TIM_ClearFlag(TIM2, TIM_FLAG_Update|TIM_IT_CC2);
TIM_ITConfig(TIM2,TIM_IT_Update|TIM_IT_CC2,ENABLE);
TIM_Cmd(TIM2, ENABLE);
}

void TIM2_IRQHandler(void)
{

   if(TIM_GetITStatus(TIM2,TIM_IT_CC2)==SET)//捕获中断
   {
       if(timer2_ch2_capture_sta&0x01)//符合条件的话说明上次捕获了高电平，那么这次捕获的一定是低电平
       {
           PPM_Time=TIM_GetCapture2(TIM2);
           if(PPM_Time>0)
               PPM_Time++;
           if(PPM_Okay==1)
           {
           PPM_Databuf[PPM_Sample_Cnt]=PPM_Time;
               PPM_Sample_Cnt++;
               if(PPM_Sample_Cnt>8)
                   PPM_Okay=0;
           }
           if(PPM_Time>7000)//识别到帧尾
           {
           PPM_Okay=1;
               PPM_Sample_Cnt=0;
           }
           digitalToggle(GPIOC,GPIO_Pin_13);
           TIM_OC2PolarityConfig(TIM2,TIM_ICPolarity_Rising);
           timer2_ch2_capture_sta=0;//清掉标志位准备开始下一次上升沿和下降沿检测
       }
       else
       {
           TIM_SetCounter(TIM2,0);//以上为清零
           timer2_ch2_capture_sta|=0x01;//高电平指示被赋值
           TIM_OC2PolarityConfig(TIM2,TIM_ICPolarity_Falling); //当捕获上升沿后改为捕获下降沿
       }
   }
   if (TIM_GetITStatus(TIM2 , TIM_IT_Update) != RESET )//超出，遥控器没有开机
   {
//       if(count>=50)
//       {
//       count=0;digitalToggle(GPIOC,GPIO_Pin_13);
//       }
//           else
//           count++;
//     PPM_Databuf[0]=0;
// PPM_Databuf[1]=0;
//     PPM_Databuf[2]=0;
// PPM_Databuf[3]=0;
//     PPM_Databuf[4]=0;
// PPM_Databuf[5]=0;
//digitalToggle(GPIOC,GPIO_Pin_13);
   }
TIM_ClearITPendingBit(TIM2, TIM_IT_CC2|TIM_IT_Update); //清除中断标志位，一定不要忘，要不然下次进不了中断

}